Gas turbine engines are used to power aircraft, watercraft, power generators, and the like. Gas turbine engines typically include a compressor, a combustor, and a turbine. The compressor compresses air drawn into the engine and delivers high pressure air to the combustor. In the combustor, fuel is mixed with the high pressure air and is ignited. Products of the combustion reaction in the combustor are directed into the turbine where work is extracted to drive the compressor and, sometimes, an output shaft, fan, or propeller. Left-over products of the combustion reaction are exhausted out of the turbine and may provide thrust in some applications.
Compressors and turbines typically include alternating stages of static vane assemblies and rotating wheel assemblies. The rotating wheel assemblies include disks carrying blades around their outer edges. When the rotating wheel assemblies turn, the blades push air axially toward an aft end of the engine. The rotating wheel assemblies also cause the air to move radial, or swirl, about a central axis of the engine as the air is pushed toward the aft end. The static vane assemblies are arranged between the rotating wheel assemblies to re-direct the radially moving, or swirling, component of the air to the axial direction.
Some vane assemblies are formed by a number of flow path components arranged circumferentially adjacent to one another to form a hoop and a plurality of endwalls arranged around the hoop of flow path components. Such vane assemblies sometimes include components having different rates of thermal expansion which may cause the components to experience areas of localized stress during heating and cooling of the vane assemblies.